Knob



M. S. BANN Feb. 6, 1962 KNOB 2 Sheets-Sheet 1 Filed June 16, 1959INVENTOR.

MICHAEL 3. BANN ATTORNE- M. S. BANN Feb. 6, 19 2 KNOB 2 Sheets-Sheet 2Filed June 16, 1959 INVENTOR.

MIcHAEL 5. BAN 11 ATTOR N Eb United States 3,019,667 KNGB Michael S.Bann, Grange County, Calif., assignor to Collins Radio Company, CedarRapids, Iowa, :1 can-porn tion of Iowa Filed June 16, 1959, Ser. No.820,827 7 Claims. (Cl. 74-528) This invention relates generally to animproved actuating knob for electronic equipment, and more particularlyto a manual control knob provided with a simple and effectiveunidirectional locking mechanism.

For some types of electronic radio equipment it is desirable to have amanual control knob incorporating a unidirectional locking member toprevent accidental actuation of the knob from the on to the offposition. To be effective, a knob of this type must be capable of easyrotation from the off to an energized position, but it must incorporatea positive locking device which prevents rotation of the knob to the offposition in the absence of a special effort exercised by the equipmentoperator.

It is therefore an object of this invention to provide a manual controlknob for electronic equipment which includes a positive spring lockingmechanism.

A further object of this invention is to provide a manual control knobof the above described type which can be easily rotated from an offposition to one of several energized positions, but which is preventedfrom free rotation to the off position by a positive locking mechanism.

Another object of this invention is to provide a manual control knobhaving a positive spring biased locking mechanism which is ineffectivewhen the knob is rotated from an off position to an energized position,and which effectively prevents the return of the knob to the offposition.

A still further object of this invention is to provide a control knobwhich requires physical effort on the part of an operator to rotate itfrom an energized to an off position, thus preventing subconscious oraccidental operation thereof.

With the foregoing and other objects in view, the invention resides inthe following specification and appended claims, certain embodiments anddetails of construction of which are illustrated in the accompanyingdrawings in which:

FIGURE 1 illustrates in front elevation the control knob and lockingmechanism in operative mounted position on a fragmentary portion of acontrol panel;

FIGURE 2 is a view in side elevation of the knob of this invention takenalong the plane of line 22 in FIG- URE 1;

FIGURE 3 is a longitudinal sectional view through the knob of thisinvention taken along the line 33 in FIG- URE l with the knob in normalposition; and

FIGURE 4 is a longitudinal sectional view at right angle to the view ofFIGURE 3, showing the knob in a raised position to disengage the lockmechanism.

Referring to FlGURE l of the drawings, a control knob 11 is mounted on arotatable center pin 13 which is supported by means (not shown) toextend through a panel member 16. On panel member 16 are indicia 22 and23; 22 representing the deenergized position of knob 11 and 23 theseveral energized positions. A skirt portion 17 is attached to thecenter pin 13 and is rotatable therewith. Pointer mark 9 is provided onthe face of skirt portion 17 for the purpose of indicating the positionof the control knob relative to indicia 22 and 23. Extending from aportion of knob 11 is a lug 19 which, in cooperation with a pin 12 setin the face of panel 16, forms a locking mechanism. Knob 11 and lug aremovable iongitudinally of center pin 13 and locking pin 12.

3,019,667 Patented Feb. 6, 1962 In FIGURE 2, center pin 13 extendthrough the center portion of tubular knob 11 and is attached to adriven shaft 14 by means of set screws 15. A cutaway section 24 isprovided in the rear portion of knob 11 to allow access to set screws15. A Rollpin 18 extends transversely through center pin 13 and rests inlongitudinal slots 19 provided in the sides of knob 11. Rollpin 18 ridesin slots 19 when knob 11 is moved longitudinally of center pin 13, andupon rotation of knob 11, the Rollpin transmits torque to centerpin 13.In some instances it may be desirable to omit center pin 13 and toattach knob 11 directly to driven shaft 14 by means of set screws 15. Inthis case Rollpin 18 would extend transversely through driven shaft 14and into slots 19 of knob 11.

In FIGURE 3, center pin 13 is illustrated as extending through thetubular opening 25 formed in knob 11. The outer end portion of theopening is of an enlarged diameter as shown at 26, thus forming a seat27 for one end of a helical spring member 21 which rests in a space 28between the sides of enlarged opening 26 and center pin 13. Center pin13 is formed with an enlarged head portion 26 which provides a seat 29for the other end of spring 21. Spring 21 reacts axially of knob 11 andcenter pin 13 to keep surface 32 of the knob in contact with skirt 17 ofthe center pin when the knob 11 is in the normal position. Knob 11 canmove longitudinally over head 20 for a distance governed by the lengthof enlarged opening 26 and the extent of compressibility of helicalspring 21.

In FIGURE 4, lug 1% extending from knob 11 is shown as being providedwith a cammed surface 30 which allows the lug to move easily over pin 12when the knob 11 is rotated from the off to an energized position. Tofacilitate a smoother camming action, pin 12 may also be provided with acam surface 31 to cooperate with surface 30 of lug 1%.

In the operation of this invention, when the knob 11 is rotated from theoff to an energized position, cam surface 39 of lug 10 cooperates withthe surface of pin 12 to cause the knob to move longitudinally of centerpin 13 against the bias of spring 21. Rollpin 18 transmits torque tocenter pin 13, causing rotation of the center pin and driven shaft 14,and as lug 10 and pin 12 move knob 11 longitudinally of center pin 13against the bias of spring 21 to allow the lug to pass easily over thepin 12, Rollpin 18 is caused to move transversely in slot 19. After lug1%) has passed over pin 12, spring 21 expands causingthe knob 13 and thelug it to snap back into position below the pin 12. If the knob 11 isnow rotated from an energized position toward the off position, lug 10engages pin 12, and knob 11 must be manually moved longitudinally ofcenter pin 13 in order that lug 19 may pass over the locking pin 12.

It should be obvious to one skilled in the art that this inventionprovides a novel and improved control knob for electronic radioequipment which incorporates a simple and effective unidirectionallocking mechanism. The arrangement and components utilized for thiinvention may be subject to numerous modifications well within thepurview of the inventor who intends only to be limited by thespecification and a liberal interpretation of the appended claims.

I claim:

1. A control knob for an instrument panel comprising a rotatable drivenshaft extending through said panel, a knob member formed with a centralopening to receive said driven shaft, a torque transmitting memberinterconnecting said driven shaft and knob member so as to allow limitedaxial movement of said knob relative to said driven shaft, and apositive unidirectional locking mechanism, said mechanism including alug member extending from said knob and a pin projecting from saidpanel, at least one of said lug or pin members having a cammed surfacewhich cooperates with the surface of the other member to cause the knobto move axially and pass easily over the pin when the knob is rotatedfrom the off to an energized position.

2. A control knob for an instrument panel comprising a rotatable drivenshaft extending through said panel, a centerpin secured to said drivenshaft, a knob member formed with a central opening to receive saidcenterpin, a torque transmitting member interconnecting said centerpinand knob members so as to allow limited axial movement of said knobrelative to said centerpin, and a positive unidirectional lockingmechanism, said mechanism including a projecting member carried by saidknob, said projecting member having a single cammed surface and a pinextending from said panel, the cammed surface of said projecting membercooperating with the surface of said pin to cause the knob to moveaxially and pass easily over the pin when the knob is rotated from theoff to an energized position.

3. A control knob for an instrument panel comprising a rotatable drivenshaft extending through said panel, a centerpin secured to said drivenshaft, a knob member formed with a central opening to receive saidcenterpin, a torque transmitting member interconnecting said centerpin,a torque transmitting member interconnecting said centerpin and knobmembers so as to allow limited axial movement of said knob relative tosaid centerpin, and a positive unidirectional locking mechanism, saidmechanism including a lug extending from said knob and a pin projectingfrom said panel, said lug and pin having cooperating cam surfaces whichcause the lug to pass easily over the pin when the knob is rotated fromthe off to an energized position.

4. A control knob for an instrument panel comprising a rotatable drivenshaft extending through said panel, a centerpin secured to said drivenshaft, a knob member formed with a central opening to receive saidcenterpin, a helical spring member seated between said knob andcenterpin within said central opening to bias the knob in the directionof the panel, a torque transmitting member extending transversely ofsaid centerpin through said knob member so as to allow limited axialmovement of said knob relative to said centerpin, and a unidirectionallocking mechanism, said mechanism including a lug which extends from aportion of said knob and a pin which projects from said panel, said lughaving a cammed surface which cooperates with the surface of said pin tocause said lug member to pass easily over the pin when the knob isrotated from the off to an energized position.

5. A control knob for an instrument panel comprising a rotatable drivenshaft extending through said panel, a centerpin secured to said drivenshaft, a knob member having aligned longitudinal slots in the sideportions thereof, said knob member being formed with a central openingto receive said centerpin, a helical spring member seated between saidknob and centerpin within said central opening to bias the knob in thedirection of the panel, a rod extending through said centerpin andresting in the aligned slots in the sides of said knob member so as toallow a limited axial movement of said knob relative to said centerpin,and a unidirectional locking mechanism including 3. lug which extendsfrom a portion of said pin which projects from said panel, said pinhaving a cammed surface which cooperates with the surface of said lugmember to cause the lug to pass easily over the pin when the knob isrotated from the off to an energized position.

6. A control knob for an instrument panel comprising a rotatable drivenshaft extending through said panel, a centerpin secured to said drivenshaft, a skirt member provided on said centerpin in a position adjacentto said panel, a knob member formed with a central tubular opening toreceive said centerpin, a spring member seated between said knob andcenterpin within said central tubular opening, said spring reactingaxially to maintain the knob member in contact with the skirt of saidcenterpin, a torque transmitting member extending transversely of saidcenterpin through said knob member, said torque transmitting memberallowing limited axial movement of said knob relative to said centerpinbut preventing rotational movement of said knob relative to saidcenterpin, a lug extending from said knob in a plane parallel to saidpanel, a pin projecting from said panel in a plane perpendicular to saidpanel, said lug and pin cooperating to form a positive unidirectionallocking mechanism for said knob.

7. A control knob for an instrument panel comprising a rotatable drivenshaft extending through said panel, a centerpin secured to said drivenshaft, said centerpin having an enlarged head portion on one endthereof, a skirt member having indicator means thereon, attached to theopposite end of said centerpin adjacent said panel, a knob member formedwith a central tubular opening to receive said centerpin, said openingbeing of extended diameter adjacent the outer face of said knob toreceive the enlarged head portion of said centerpin, a helical springmember seated in the enlarged opening in said knob, said spring memberreacting axially between the knob and the enlarged head portion of thecenterpin to maintain the knob member in contact with the skirt of saidcenterpin, a rod etxending transversely of said centerpin through saidknob member, said rod allowing limited axial movement of said knobrelative to said centerpin but preventing rotational movement of saidknob relative to said centerpin, a lug extending from said knob in aplane parallel to said panel, a pin projecting from said panel in aplane perpendicular to said panel, said lug and pin members providedwith cooperating cammed surfaces which cause said lug member to passeasily over the pin when the knob is rotated from an oif to an energizedposition.

References (Zited in the file of this patent UNITED STATES PATENTS496,967 Archer May 9, 1893 1,330,860 Gale Feb. 17, 1920 2,239,525Johnson et al. Apr. 22, 1941 2,502,915 Atkins et al. Apr. 4, 19502,841,034 Greene July 1, 1958 FOREIGN PATENTS 607,542 Germany Jan. 2,1935 676,633 Germany June 10, 1939 UNITED STATES PATENT OFFICECERTIFICATE OF CORRECTION Patent No, $019,667 February 6 1962 Michael S.Bann ed that error appears in the above numbered pat- It is herebycertifi and that the said Letters Patent should read as ent requiringcorrection corrected below.

Column 3, line 62 before "including" insert u said mechanism column 4line 1 before "pin", first occurrence insert knob and a Signed andsealed this 5th day of June 1962.

(SEAL) Attest:

DAVID L. LADD ERNEST W. SWIDER Commissioner of Patents Atteating Officer

